Q: Tuning Air/Fuel Mixture on 1977 Bus with Fuel Injection

[Happyfolk]

[SGKent]

[equinox]

"Stay out of the AFM until every other thing on the bus is done. I am sure there will be a good discussion over how many people mess those up."

lol, no doubt. The mechanic that had it had to fix the "flap" from a backfire and did some adjusting in there. This may be part of the issue (not set right). I still worry this "fix the flap" may not have been done right or a permanent fix, so worry and maybe I should just get a new/refurbished unti, but I guess we'll see and check everything out first.

Again, I'm behooved at their incompetence to have experience people test drive it and say "it's done" and find out the upper shock on the rear drivers side was backed out 1/2" and now we know there is an issue with the purge valve diaphram and not getting full advance. Both of these issues should have been identified. They adjusted the timing. They adjusted the AFM. Am I wrong? I don't think so. Incompetence.

[SGKent]

[Wildthings]

[equinox]

Your off base Wildthings

No, when I pay for them and in part to fix the AFM and set it and timing and set it and in that TOTAL advance and call me and say it is finished and these weren't around the corner mechanics, these are Certified Bosch Service Center and VW/Porsche experts, you bet you god damn ass, I expect it to be done right and before they give me a jingle. ANYONE would.

These were components and issues they were dealing with....or are you missing that point? ANY reasonable person would expect it to be done right. ...and a shock that is banging around? You can't hear that on a funking test drive? OIt wasn't there when I took it in, so something they did, maybe then they installed the new engine bay foam seal, who knows. You need a hearing aid. Good Grief.

What should have happened are all of these issues with timing, idle, AFM should have been fixed and on the test drive should have picked up on the shock issue and contacted the customer and notified him of this or just bolt and torqued it out of courtesy. Don't get me started on the new battery they "lost" then initially I can tell you they had NO intention of replacing it. It was only after I bitched they wrote me a check, which took 4 weeks. FUNK THEM!

[Randy in Maine]

We are making progress on this though....

So far we have improved all of the electrical connections at the battery, starter and grounds. We have looked for and removed some of the vacuum leaks. And we have gotten the ignition system back in working order with correct timing.

Next up we will be testing out our fuel pressure, and doing the pre-lim testing of the FI system using this handy little chart....

https://www.type4.org/manuals/ljet/

In no time we shall make this bus a good driver to be enjoyed by the owner and hopefully some kids to go camping in.

It just takes some time and some basic testing. We will get there.

[Wildthings]

[equinox]

"In no time we shall make this bus a good driver to be enjoyed by the owner and hopefully some kids to go camping in. "

That's what I'm talkin' about! I did a few days at the Buses By the Beach event, but after I got home and calculated the MPG was off, it's been down until I get this resolved, but once it's done...I'm going camping and have vacations again in August and September scheduled so I don't miss out on the Summer again. Now to get this thing going and hit the window of these event. Actually I have a homecoming event in 2 weeks I'm planning on taking it to along with the Hines Drive and Dream Cruises!

I got the Vacuum/Pressure Pump today! Soo, I'll be verifying hose and the purge valve about holding pressure in the morn.

Thanks again for your help!

[LouFilia]

I've been following this as I am a newcomer to the VW buses and your situation is like mine and I have a few suggestions that might help you out (or not so feel free to ignore).

First off, great job listening to people here. It's easy to see your progress. As you figured out there are some great people to listen to (like SGKent and RandyInMaine) and some to take with a grain of salt.

IF YOU DON'T HAVE A FUEL PRESSURE GAUGE, GET ONE. You will need it for the next step that RandyinManine is heading to.

Please post your pictures on the Samba. Many people are not looking at them and the pictures have their own story to tell (like your AFM is set at an extreme, I'm still going through the same process myself and have not got to the afm, but compared to the pictures on ratwell it's way off). You will get much better replies.

The biggest thing is that your attitude to your bus has changed. You started out wanting to get one problem fixed, but you have now realized that the only way to get good maintenance and repair results is to become your own mechanic.

We (The Samba) need a post that helps people in our situationA post that is titled some thing like, 'Getting to know your L-jet Injected bus, aka Your first step to becoming a L-Jet expert in the 21st Century.

You need need a plan that gets you both ready to adjust the AFM and gives you a basic set of diagnostic skills. I had hoped to convince Colin to be at my house right now, but I failed, so treat my plan as a work in progress, I am sure I'll miss a couple of things as I'm typing this off the top of my head on my freaking phone, but something like this, I'd start at the beginning so that you have all the info, but feel free to miss the first one

Check compression and valves (I use the ratwell method on the valves) Look at and read the plugs
Check timing and set to itinerant method (28* all in, no vacuum).
Check for Vacuum leaks. (they have given you lots of ideas here, please re-read. I like to use suck and hold, soapy water, disconnect and plug, and smoke from my smokey treat
When your doing the vacuum check be sure that the decal valve, eec, dis, and others hold a vacuum and I can usually hear or see them working while sucking
Check operation of AAR
Check fuel pressure (this is why you need the fuel pressure gauge, they are available at most parts stores)
Check injector function (I made sure mine were working somewhat just by disconnecting to make sure they were firing, you also need to test resistance and flow as per specs listed in one of the many manuals).
You need to check the CSV. Both that it functions (easy to do, per Bentley's, it's just another injector) and that it doesn't leak (I have no clue how to test, but I will learn)
I also haven't even looked at my TTS (Thermo time switch), but that's part of the deal
Oh crap, I almost forgot checking TSII (temperature sensor two) This is critical and you can read all about on itinerant 4. I imagine one needs to check TS1 also, but all I know about it at the moment is that it is part of the AFM.

I have downloaded all the manuals listed here on the samba, all of colins drawings, put them in a three ring binder with all the receipts for my bus, and keep it with my Bentley's. I hope this helps. My only other suggestion would be that you plan on driving your bus lots and I don't think you have a temperature gauge of any kind. Many people use oil temperature (my bus came with one already), but the best is a Cylinder Temp Gauge and the preferred one is Dakota Digital.
_________________
'78 Westy (P22), 2.0FI (GE), 4speed (CP), thought I was buying a VW, ended up with a Bentley.

[busdaddy]

[LouFilia]

Like that yes, but much simpler. That would be how I learned (am learning, edit) to go through my system, but it's very complicated. The original texts have got to be nearly impossible to decipher if you don't show up with a lot of pre-knowledge. I was thinking of something much easier like a list with links to find the right articles, like
adjust valves, use the ratwell method here http://www.ratwell.com/technical/HydraulicLifters.html.
Check compression see article or post here, etc.

In general, I was referring to everybodies desire to open up their afm and adjust. The Samba always tells them to make sure everything else is working (great advice as it's quite often something else), I think a list stating what the everything was would be useful. Minimally I will end up making one for myself

Equinox
So sorry if this hijacks the thread, you're doing great and your bus is well on the way to running better. I seem to piss VW people off with my posts and I don't know why. I have avoided posting for that reason, but I really want to see you succeed. (edit)
As I looked over the list at Ratwell, I can already see a couple of things I glossed over like verifying the series resistors are delivering the right juice and I assumed your double relays were working perfectly. (I am pretty sure both are fine, but we're trying to learn about our buses and how to work on them in total).

In general, I was referring to everybodies desire to open up their afm and adjust. The Samba always tells them to make sure everything else is working (great advice, as it's quite often something else), I think a list stating what the everything was would be useful.
I think this is what happened to you at the shop. They failed to find the leaky EEC and tried to compensate by adjusting the afm.

Colin's words on Vacuum leaks "Vacuum Leaks? - injector small donut seals, intake runners, auxiliary air regulator elbow, breather gasket and hose, dipstick hat seal and boot, brake booster circuit (check by just pulling it off and blocking, if engine runs differently, check further)"

Also equinox, you'll get better replies if you put your bus's details in your signature line, (for example right below here it says something like '78 westy 2-liter fuel injected (GE code engine) 4speed (CP code tranny)
_________________
'78 Westy (P22), 2.0FI (GE), 4speed (CP), thought I was buying a VW, ended up with a Bentley.

[equinox]

Thanks so much again everyone. Well, it's the weekend, but I spent the rest of the day after work out on a friends new boat. Today, I had some running around I had to do and haven't really felt all that well and it's 90 deg and 100% humidity and I have some things to do yet like cut lawn and spray. So nothing looked at yeat, but tomorrow will be the day first thing in the morning and I will review what everyone said.

LouFilia - That you so much for your insite. Yes, it's becoming more aparent to me that a "checklist" procedure needs to be developed. We're already doing it here, but I think it wuold be great and folks could go step by step!

Other people have gotten their hands into my bus and may in other's cases, so it may be a little painful, but yes, everything should be double-checked and yes, in that 1. you need to the tools, and ageed 2. YOU become your mechanic!

The new gauge I bought does vacuum and pressure, so I may be able to use that tomorrow.

The shop already checked the compression as well as efficiency of the valvetrain and again, can retest, but the results were good (like 5% or less for 3 cylinders and I think one was like 13% loss).

First things first and I'll dig more into the vacuum issue. The shop did a smoke test and said no more leaks, but what we found was there was in fact a leak with the ported vacuum and purge valve and in that no vacuum advance! I think once vacuum is complete, the next step will be ARF and as I said, there was an issue of the flap getting damaged during a backfire condition and they "fixed" it (how I have no idea) and may have adjusted it (but it seems aparent a readjustment is needed for optimal performance). We'll see what happens!

[equinox]

Ok guys, here's what transpired today...

1. I have no way of testing fuel pressure so that will have to wait for another day. As the engine starts and runs fine, this should not be related to any problems anyway and only a heiristic check.
2. I checked the vacuum lines and did not find any additional leaks. The purge valve still is the only one detected.
3. However, after josling the hoses, the engine was having a hard time holding idle. I rechecked the hoses and again and everything seemed fine. When I was looking around, I seen that the hose in Photo A is connected to a plastic sleeve and goes into that rubber boot. That sleeve and hose were pulled out. When I plugged it back in, again the engine idled and ran fine. I should probably secure it a little better though if it can just be bumped loose!
4. I kept the one hose plugged with a Golf-T and ran the engine for more like 30 minutes before doing a data log with the LM-2. What a great device! I don't have any RPM or speed or anything, just datalogging O2. - Photo B
5. I was at the bottom of a small hill (overpass here in Michigan, we don't have real hills near Detroit) and this is what the LM-2 logged. - Photo C
6. I then stopped the data log from previous and started a new one for the drive back home. Really the O2 does not idle at 12.0, it's more like 11.2 - Photo D
7. What is this thing - Photo E - It's completely disconnected! The fat hose goes nowhere - The fat right hose goes into that purge valve - Photo F - and that small hose on the right again goes to a T-fitting that goes nowhere - Photo E

Let me know your thoughts.

Photo A:

Photo B:

Photo C:

PhotoD:

Photo E:

Photo F:

[/img]

[SGKent]

set the idle mixture to the tag on the inside of the engine door for best performance. Your at speed mixture appears fine. Take it to a smog shop when you are done and have them do a pre-smog on it to see how clean it runs on a dyno at 15 mph and 25 mph. That will tell you if it is perfect or not. Looks close to me.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[equinox]

Ok, a couple things in regard to this request...

1. There is no tag in the engine compartment
2. I live in Michigan and we have no SMOG or emissions testing programs anymore, so that may be difficult.

Any other suggestions?

What about those other pictures and the charcoal canister or whatever that is and purge valve being disconnected? If left this way, what issues would this cause?

In the meantime, I filled it up yesterday and am monitoring the MPG and since the vacuum advance is working now and see where we are. I didn't calculate it, but it appears to be going through gas still pretty good and if the gauge is correct. I had accumulated like 40 miles and the gauge was down ~1/8 a tank! Seemed pretty substantial from 35,000 ft, but we'll see.

[Randy in Maine]

The fuel gauges are usually not very accurate. I prefer to go for about 150 miles then do a fill up to figure out my MPG.

There used to be a guy around here that did a lot of tuning of various sports cars/vintage cuisers/ratrods/carbed vehicles and similar who was quite adept at tweaking them to get the most power out of them. Long dead, but perhaps there is someone near you that does that sort of thing. I would imagine that someone in themotor city is still doing that.

I forget do you have a cylinder head temp gauge in this thing?

[SGKent]

[equinox]

Yeah, that's what I do, just run through the tank, fill it up and divide by the miles driven. We'll see what it turns out to be.

No, there's no tag in the engine door on the back. Must have been removed. I have the Official Service manual and can look it up.

So, you think the AFM is working ok then?

I'll secure the hose without clamp and one what came out of that boot the other day in the meantime.

You still didn't answer my questions if there is any issue running it the way it is and basically with the charcoal canistor and purge valve system disconnected?

[Randy in Maine]